National survey data suggest prevalence of problem behaviors in young children is between 10-25%. As children enter preschool and begin to navigate social situations outside the home, problem behaviors interfere with social development placing children at risk for problematic peer relations and delayed social skills. Without intervention, social and behavioral problems tend to persist and even escalate over time and, in turn, have a tremendous impact on the development of child psychopathology. The goal of this SBIR project is to create and test a preschool version of an existing evidence-based small group social skills training program (SSGRIN; Social Skills Group Intervention) in order to make it applicable for younger children. The complete SSGRIN-P intervention program will consist of 10 sessions addressing specific social skill sets (i.e., Getting Acquainted, Consequences, Feelings, Communication, Empathy, Friendship, Cooperation, Problem Solving, Initiation, Review). For the Phase I prototype, the session scripts for the first five sessions will be developed, as well as the Professional Manual. All needed materials for Session 1-5 activities (e.g., puppets, music samples) will also be developed for the prototype. The multi-media components accompanying the first five sessions will be developed, including five in-session video segments and interactive web-based resources for children, parents, and professionals. The prototype interactive web-based resources will include four interactive games and activities for children to practice the skills taught in Sessions 2-5, as well as website links and resource lists of related books and other media for parents and professionals. Parent handouts will also be developed describing supplemental activities to implement at home to accompany each session. Once the prototype is complete, an initial test of feasibility will be conducted within two targeted market segments (school- and community-based child mental health professionals; n=30 each) and with targeted end users (preschoolers and parents; n=30 each). Phase I findings will provide the foundation for the development and testing of the complete SSGRIN-P intervention program during Phase II. Once SSGRIN-P is finalized, a scientific evaluation of the efficacy of this product will be conducted in Phase II through a randomized treatment-control experimental design examining changes in children's social relations, behavior, and social skill level. The long-term objective of this product is to decrease the development of psychiatric disorders due to socio- emotional deficits. Therefore, this project directly addresses the research interest of the Division of Pediatric Translational Research and Treatment Development to support programs of research and research training with the ultimate goal of preventing and curing childhood psychopathology. National survey data suggest the prevalence of problem behaviors in young children is between 10-25% (Webster- Stratton & Hammond, 1997). As children enter preschool and begin to navigate social situations outside the home, problem behaviors interfere with social development placing children at risk for problematic peer relations and delayed social skills. Without intervention, social and behavioral problems tend to persist and even escalate over time and, in turn, have a tremendous impact on the development of child psychopathology. Development of psychiatric disorders due to socio-emotional deficits is a public health concern with annual US economic, indirect cost of mental illnesses estimated at $79 billion. Development and implementation of efficacious interventions such as SSGRIN-P can reduce these costs. [unreadable] [unreadable] [unreadable]